Yellow disazo dye.



' No Drawing.

UNITED STATES PATENT OFFICE.

ARTHUR ZAB-T, or v'onwiNKnn, AND HU o sonwnrrznn, or ELBERFELD, GERMANY. 1 ASSIGNOBS To FARBENFABnI ENvom/i. FRIEDR. BAYER & 00.,01? ELBEBFELD,

GERMANY, A CORPORATION on GERMANY.

YELLOW DISAZO DYE.

To all whom ttmay concern: I

Be it known that: we, ARTHUR ZART- and HUGO SonwErrzER, doctors of philosophy, chemists, citizens of the German Empire,,residing, respectively, at Vohwinkel and Elberfeld, Germany, have invented new and useful Improvements in'New Yellow Disazo Dye, of which the following is'a specification.

The present invention relates to the manufacture and production of new azo dyestuffs capable of dyeing unmordanted cotton in from yellow to orange shades which" on being developed on the fiber become fast to washing.

The process for their production consists I in convertin' into urea compounds 'carboxylic acids 0 nitroaminoazo compounds in which the nitroand amino groups are contained in dlfi'erent nuclei or of the corresponding diaminoazo compounds in which.

one hydrogen ofone amino group is replaced by an aci pounds containing an acid radical. The

urea compounds arefproduced in the usual way by treatment. with phosgene. The new dyes are after being dried and pulverized in the shape of their alkaline saltsdark yellow powders soluble in water with a yellow color and soluble in concentrated sulfuric acid with aireddish to violet color. Upon reduction with stannous chlorid and hydro-- chloric acid a diamincarboxylic acid and an urea of a diaminis obtained, which is split up into carbonic acid and a diamin.

In order-to illustrate the new process more fully the following example is given, the

parts being by weightz-The dye obtained from 180 parts of diazot'ized monoformyl- 3.5-diaminobenzoic-acid and 137 parts ofcresidin -is after solution in aqueous sodium'carbon- I Specification of Letters Patent.

radical and in subsequently reducing the products obtained fromthe nitrov ate converted into the urea compound by treatment with phosgene, then salted out, filtered olf and boiled for 20 minutes with a l per cent. caustic soda lye to eliminate the formic acid radical. "It is then salted out and filtered off. It i's after being dried and pulverized in the shape of its sodium salt a dark yellow powder soluble in water with a yellow color and soluble in concentrated sulfuric acid with a red color; yielding upon reduction with stannous chlorid and hydrochloric acid symmetrical diamino benzoic acid and the urea of aminocresidin CH3 CH3 CH3 ACHg which is further decomposed into paramethoxy ortho meta diaminotoluene and carbonic acid. It dyes cotton' yellow yielding a pure yellow of good fastness to washing after combination with diazotized paranitranilin. The shade thus" produced can be well discharged. Instead'of formyl-diaminobenzoic acid 3- nitro-5-aminobenzoic acid, 4-,oxalylamino-2- aminobenzoic acid, etc., can be used.

' As second component any other suitable amin can be used c, g. anilin, toluidins. xylidins', acidyidiamins, naphthylamins, etc.

We claim 1.' The'herein described new dyestufis be ing nreas of carboxylic acids of aminoazo compounds containing free amino groups, I

which dyes are after being dried and pulverized in the shape of their alkaline salts dark yellow powders soluble in water with a yellow and soluble inconcentrated sulfuric acid with a reddish to violet color; yielding upon reduction with stannous-chlo- I Patented Aug. 22, 1911. Application filed April 25, 1911. Serial No. 623,176.

rid and hydrochloric acid a diamino carboxylic acid and an urea of a diamin, which,

is further decomposed into carbonic acid and a diamin; dyeing cotton yellow to orange shades which on being developed on the fiber become fast to washing, substantially as described.

2. '-The herein described new dyestuflfbeing theurea of the azo compound from 3.5-

which is after being dried and pulverized in'the shape of its sodium salt a dark yellow powder soluble in Water with'a yellow colorv and soluble in concentrated sulfuric, ac'd with a i'ed co lor; yielding upon reduc on with stannou's 'chlorid and hydrochloric acid 3. 5-phenylenediamih carboxylic .acid 'and the .urca of aminooresidin which is further decomposed into para-methoXy-ortho-metadiaminotolnene. and carbonic acid; dyeing cotton yellow shades fast to Washing after combination with di-azotized para-nitranilin, substantially as described. v

In testimony whereof we have hereunto scribing. Witnesses.

ARTHUR ZART. [my

I HUGO SCHWEITZER; [1. s.] Witnsssi GHAs. J; WRIGHT, ALFRED-HENKEL.

Copies of this patent, may be obtained for five cents each, by addressing the Y Washingto'n, 1). O.

Commissioner of Patents,

set our hands in the presence of two sub- 

